Nutrition and health

Objectives:
Is there a causal relationship between dairy products or calcium supplements and the reduction in fat mass and BMI among overweight or obese adults?

Study design:
This review article included 10 and 14 RCTs with ≥ 12 weeks interventions of calcium supplements and dairy products among overweight (BMI>25) or obese (BMI>30) adults aged ≥18.

Results and conclusions:
The investigators found that dairy products significantly reduced fat mass among overweight or obese adults [SMD = -0.40, 95% CI = -0.77 to -0.02].
This reduction was also significant in the analysis of RCTs with low risk of bias scores.

The investigators found that dairy products significantly reduced BMI among overweight or obese adults [SMD = -0.46 kg/m², 95% CI = -0.67 to -0.26].
This reduction was also significant in the analysis of RCTs with low risk of bias scores.

The investigators found that calcium supplements significantly reduced fat mass among overweight or obese adults [SMD = -0.15, 95% CI = -0.28 to -0.02].
However, this reduction was not significant in the analysis of RCTs with low risk of bias scores.

The investigators concluded there is a causal relationship between dairy products without distinction of fat percentage and the reduction in fat mass and BMI among overweight or obese adults.

Original title:
Meta-analysis of randomized controlled trials on calcium supplements and dairy products for changes in body weight and obesity indices by Hong JY, Lee JS, [...], Kim MK.

Link:
https://pubmed.ncbi.nlm.nih.gov/33292017/

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Objectives:
Does pistachio supplementation reduce obesity risk?

Study design:
This review article included 11 randomized controlled trials (RCTs) with 1,593 subjects.

The assigned pistachio intake was below 50 g/d in 3 studies.
Intervention times were shorter than 12 weeks in 4 studies.
There was no significant publication bias.

Results and conclusions:
The investigators found compared to the control diet group, the pistachio supplementation regimen significantly decreased BMI [-0.18 kg/m², 95% CI = -0.26 to -0.11 kg/m², p 0.001, I2 = 29.8%, p = 0.180].

The investigators found compared to the control diet group, the pistachio supplementation regimen did not significantly change waist circumference [net change = 0.76 cm, 95% CI = -0.11 to 1.63 cm, p = 0.087, I2 = 7.0%, p = 0.340].

The investigators found compared to the control diet group, the pistachio supplementation regimen had no effect on body weight [net change = 0.22 kg, 95% CI = -0.50 to 0.07 kg, p = 0.141, I2 = 0.0%, p = 0.962].

The investigators concluded compared to a controlled dietary intake, an adequate amount of pistachio supplementation lowers BMI without increasing body weight, which supports the view that pistachio consumption is beneficial for human health.

Original title:
The relationship between pistachio (Pistacia vera L) intake and adiposity: A systematic review and meta-analysis of randomized controlled trials by Xia K, Yang T, […], Chen XZ.

Link:
https://journals.lww.com/md-journal/Fulltext/2020/08210/The_relationship_between_pistachio__Pistacia_vera.7.aspx

Additional information of El Mondo:
Find more information/studies on nut consumption and obesity/overweight right here.

Objectives:
There are numerous trials reported the effect of alpha-lipoic acid (ALA) on obesity measurements; while no summarised dose-response meta-analysis is available to address the effects of dose and duration of ALA supplementation on obesity measurements. Therefore, this review article has been conducted.

Does alpha-lipoic acid supplementation improve obesity measurements including weight, body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and fat mass (FM)?

Study design:
This review article included 18, 21 and 8 RCTs of ALA-weight, ALA-BMI, ALA-WC, respectively.

Results and conclusions:
The investigators found in two-class meta-analysis, alpha-lipoic acid supplementation significantly reduced weight [WMD = -2.29 kg, 95% CI = -2.98 to -1.60, p 0.01] and BMI [WMD = -0.49 g/m², 95% CI = -0.83 to -0.15, p = 0.005] but had no effect on waist circumference [WMD = -2.57 cm, 95% CI = -8.91 to 3.76, p = 0.426].

The investigators found while the dose-response meta-analysis revealed that the duration of alpha-lipoic acid supplementation was a significant factor affecting waist circumference reduction [p non-linearity = 0.047].
While no evidence of departure from linearity was observed for other variables; moreover, subgrouping also revealed that gender could be an important factor affecting the alpha-lipoic acid impact on waist circumference, which was significant among women [WMD = -4.099, 95%CI = -7.837 to -0.361, p = 0.032].

The investigators concluded that alpha-lipoic acid supplementation reduces BMI, weight in a two-class meta-analysis without evidence of departure from linearity in terms of dose or duration. While the association of alpha-lipoic acid supplementation on waist circumference is dependent to the duration of the study. Although further trials evaluating the other obesity measurements specially central obesity will be helpful to infer a more reliable result.

Original title:
Alpha-lipoic acid supplementation significantly reduces the risk of obesity in an updated systematic review and dose response meta-analysis of randomised placebo-controlled clinical trials by Vajdi M and Farhangi MA.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32091656

Additional information of El Mondo:
Find more information/studies on fat and obesity/overweight right here.

Objectives:
Does coenzyme Q10 supplementation reduce body weight and body mass index (BMI) of patients in randomized controlled clinical trial studies (RCTs)?

Study design:
This review article included 17 RCTs.

Results and conclusions:
The investigators found results of random-effect size meta-analysis showed that supplementation with coenzyme Q10 had no significant decreasing effects on body weight [WMD = 0.28 kg, 95% CI = -0.91 to 1.47, p = 0.64] and BMI [WMD = -0.03, 95% CI = -0.4 to 0.34, p = 0.86] of study participants.
No significant because the calculated p-value of 0.64 was larger than the p-value of 0.05.
Subgroup analysis revealed that dosage of Q10 and trial duration could not differ the results of Q10 supplementation.

The investigators concluded that coenzyme Q10 supplementation has no decreasing effects on body weight and BMI.

Original title:
Effect of Q10 supplementation on body weight and body mass index: A systematic review and meta-analysis of randomized controlled clinical trials by Saboori S, Rad EY, […], Falahi E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31336462

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Objectives:
Results regarding the association between fish intake and risk of metabolic syndrome (MetS) are ambiguous. Therefore, this review article has been conducted.

Does fish consumption reduce risk of metabolic syndrome?

Study design:
This review article included 10 cross-sectional studies and 6 cohort studies.

Results and conclusions:
The investigators found fish consumption significantly reduced risk of metabolic syndrome with 20% [OR = 0.80, 95% CI = 0.66 to 0.96, p = 0.017, I2 = 62.9%] in cohort studies.
However, this reduced risk was not significant in cross-sectional studies [OR = 0.80, 95% CI = 0.70 to 1.02, p = 0.085, I2 = 50.1%].
Significantly because OR of 1 was not found in the 95% CI of 0.6 to 0.96. OR of 1 means no risk/association.

The investigators found a significant non-linear association between fish intake levels and risk of metabolic syndrome [p for non-linearity = 0.010].

The investigators concluded that fish consumption reduces risk of metabolic syndrome when combining data from prospective cohort studies. Further studies are needed to confirm such an effect.

Original title:
A systematic review and meta-analysis of the association between fish consumption and risk of metabolic syndrome by Karimi G, Heidari Z, [...], Haghighatdoost F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32127332

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Find more information/studies on fish consumption and obesity/overweight right here.

Objectives:
Has flavonoid supplementation potential against obesity?

Study design:
This review article included 58 RCTs.
Analysis endpoints were calculated as the mean difference between baseline and post-treatment.
Flavonoids were in subclasses of flavanols, flavonols, isoflavones, flavanones, anthocyanins and proanthocyanidins. They were mostly in the form of supplements and dosages varying from 40 to 1300 mg/day.

Results and conclusions:
The investigators found among flavonoid subclasses, flavanols showed potential for decreasing BMI, in the overall population [MD = -0.28 kg/m², p = 0.04, n = 21] and in the subgroups of Asians [MD = -0.42 kg/m², p = 0.046, n = 13], ages 50 years [MD = -0.50 kg/m², p = 0.008, n = 14], BMI ≥25 kg/m² [MD = -0.30 kg/m², p = 0.049, n = 15] and at doses ≥500 mg/day [MD = -0.36 kg/m², p = 0.049, n = 12].

The investigators found among flavonoid subclasses, isoflavones also significantly decreased BMI of non-Asian populations [MD = -0.26 kg/m², p = 0.035, n = 13] and doses ≥75 mg/day [MD = -0.34 kg/m², p = 0.027, n = 8].

The investigators found in the overall assessment, flavanols also significantly decreased waist circumference [MD = -0.60 cm, p = 0.02, n = 18] but had no significant effect on body fat percentage.

The investigators found the available trials did not reveal significant effects from flavonols, flavanones and anthocyanins on the specified anthropometric measures.

The investigators concluded that flavanols, particularly ≥500 mg/day and isoflavones, particularly ≥75 mg/day have potential against obesity.

Original title:
Flavanols are potential anti-obesity agents, a systematic review and meta-analysis of controlled clinical trials by Akhlaghi M, Ghobadi S, […], Mohammadian F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29759310

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Find more information/studies on flavonoids and overweight right here.

Objectives:
Carbohydrate-restricted diets may increase low-density lipoprotein cholesterol (LDL-cholesterol or bad cholesterol) and thereby cardiovascular risk. Therefore, this review article has been conducted.

Do carbohydrate restriction diets increase cholesterol and triglycerides levels in overweight/obese adults?

Study design:
This review article included 8 RCTs with a total of 1,633 participants, of which 818 in carbohydrate-restricted diet group (intervention group) and 815 low-fat diet group (control group).

All RCTs had more than 100 participants with duration of at least 6 months.

Results and conclusions:
The investigators found when compared with low-fat diets, carbohydrate-restricted diets showed no significant difference in LDL-cholesterol levels after 6, 12 and 24 months.
Although an overall pooled analysis statistically favoured low-fat diets [0.07 mmol/L, 95% CI = 0.02-0.13, p = 0.009], this was clinically insignificant.

The investigators found when compared with low-fat diets, carbohydrate-restricted diets significant increased HDL-cholesterol (good cholesterol) levels [0.08 mmol/L, 95% CI = 0.06-0.11, p 0.00001] after 6 and 12 months.
These favourable changes were more marked in the subgroup with very-low carbohydrate content [50 g/d: 0.12 mmol/L, 95% CI = 0.10-0.14, p  0.00001].

The investigators found when compared with low-fat diets, carbohydrate-restricted diets significant reduced plasma triglycerides levels [-0.13 mmol/L, 95% CI = -0.19 to -0.08, p  0.00001 after 6 and 12 months.
These favourable changes were more marked in the subgroup with very-low carbohydrate content [50 g/d: -0.19 mmol/L, 95% CI = -0.26 to -0.12, p = 0.02].

The investigators concluded large randomized controlled trials (RCTs) of at least 6 months duration with carbohydrate restriction, particularly 50 g/d carbohydrates, is superior in improving HDL-cholesterol and triglycerides levels in overweight/obese adults when compared with low-fat diets. Dietary guidelines should consider carbohydrate restriction as an alternative dietary strategy for the prevention/management of dyslipidemia for populations with cardiometabolic risk.

Original title:
Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: a systematic review and meta-analysis by Gjuladin-Hellon T, Davies IG, […], Amiri Baghbadorani R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30544168

Additional information of El Mondo:
Find more information/studies on carbohydrate, cholesterol and overweight right here.

50 grams of carbohydrates per day corresponds to a diet with 10 En% carbohydrates.
The easiest way to follow a diet with 10 En% carbohydrates is to choose only meals/products with 10 En% carbohydrates.
However, the most practical way to follow a diet with 10 En% carbohydrates is all meals/products that you eat on a daily basis should contain on average 10 En% carbohydrates. Check here which products contain 10 En% carbohydrates.

Objectives:
Cocoa and dark chocolate (DC) have been reported to be effective for health promotion; however the exact effect of cocoa/dark chocolate on anthropometric measures have not been yet defined. Therefore, this review article has been conducted.

Has cocoa/dark chocolate supplementation positive effect on weight, BMI and waist circumference (WC)?   

Study design:
This review article included a total of 35 RCTs, investigating the effects of cocoa/dark chocolate on weight, BMI and waist circumference.

Results and conclusions:
The investigators found meta-analysis did not suggest any significant effect of cocoa/dark chocolate supplementation on:
-body weight [-0.108 kg, 95% CI = -0.262 to 0.046 p = 0.168]
-BMI [-0.014 kg/m², 95% CI = -0.105 to 0.077, p = 0.759] and
-WC [0.025 cm, 95% CI = -0.083 to 0.129, p = 0.640].

The investigators found, however, subgroup analysis revealed that weight and BMI were significantly reduced with ≥ 30g chocolate per day during 4-8 weeks.

Furthermore, supplementation of ≥ 30g chocolate per day during 4-8 weeks significantly reduced waist circumference in non-linear fashion [r = 0.042, p-nonlinearity = 0.008].

The investigators concluded that ≥ 30g chocolate per day during 4-8 weeks reduce weight, BMI and waist circumference.

Original title:
Does cocoa/dark chocolate supplementation have favorable effect on body weight, body mass index and waist circumference? A systematic review, meta-analysis and dose-response of randomized clinical trials by Kord-Varkaneh H, Ghaedi E, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29553824

Additional information of El Mondo:
Find more information/studies on meta-analysis, chocolate consumption and overweight right here.

Objectives:
Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest. Therefore, this review article has been conducted.

Do dietary carotenoids reduce risk of metabolic syndrome?  

Study design:
This review article included 11 cross-sectional studies.
Publication bias was absent and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.

Results and conclusions:
The investigators found dietary total carotenoids intake significantly reduced risk of metabolic syndrome with 44% [pooled OR = 0.66, 95% CI = 0.56-0.78, 1 SD ∼ 0.82 µmol/L, n = 5 studies]. This reduced risk was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin.

The investigators found no association between retinol (vitamin A from animal products) and risk of metabolic syndrome [pooled OR = 1.00, 95% CI = 0.88-1.13, 1 SD ∼ 2.14 µmol/L, n = 6 studies].

The investigators concluded that carotenoids, particularly β-carotene, followed by α-carotene and β-crypotoxanthin may reduce risk of metabolic syndrome. May reduce because this review article only included cross-sectional studies and no cohort studies.

Original title:
Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis by Beydoun MA, Chen X, [...], Canas JA.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30202882

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Objectives:
What are the effects of ginger intake on weight loss, glycemic control and lipid profiles among overweight (BMI>25) and obese (BMI>30) subjects?

Study design:
This review article included 14 RCTs with in total of 473 subjects.

Results and conclusions:
The investigators found that supplementation with ginger significantly decreased among overweight (BMI>25) and obese (BMI>30) subjects:
-body weight (BW) [SMD -0.66, 95% CI = -1.31 to -0.01, p = 0.04];
-waist-to-hip ratio (WHR) [SMD = -0.49, 95% CI = -0.82 to -0.17, p = 0.003];
-hip ratio (HR) [SMD = -0.42, 95% CI = -0.77 to -0.08, p = 0.01];
-fasting glucose [SMD = -0.68, 95% CI = -1.23 to -0.05, p = 0.03] and;
-insulin resistance index (HOMA-IR) [SMD= -1.67, 95% CI = -2.86 to -0.48, p = 0.006].

The investigators found that supplementation with ginger significantly increased HDL-cholesterol (good cholesterol) levels [SMD = 0.40, 95% CI = 0.10 to 0.70, p = 0.009] among overweight (BMI>25) and obese (BMI>30) subjects.

The investigators found, however, that supplementation with ginger had no detrimental effect on:
-body mass index (BMI) [SMD = -0.65, 95% CI = -1.36 to 0.06, p = 0.074];
-insulin [SMD = -0.54, 95% CI = -1.43 to 0.35, p = 0.23];
-triglycerides [SMD = -0.27, 95% CI = -0.71 to 0.18, p = 0.24];
-total cholesterol [SMD = -0.20, 95% CI = -0.58 to 0.18, p = 0.30] and;
-LDL-cholesterol [SMD = -0.13, 95% CI = -0.51 to 0.24, p = 0.48].

The investigators concluded that ginger intake reduces body weight, waist-to-hip ratio, hip ratio, fasting glucose and insulin resistance index and increases HDL-cholesterol (good cholesterol), but has no affect on insulin, BMI, triglycerides, total- and LDL-cholesterol (bad cholesterol) levels among overweight and obese subjects.

Original title:
The effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: A systematic review and meta-analysis of randomized controlled trials by Maharlouei N, Tabrizi R, […], Asemi Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29393665

Additional information of El Mondo:
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Persons with overweight are advised to choose products/meals with maximum 30 En% fat, maximum 7 En% saturated fat, maximum 0.2 grams salt per 100 kcal and minimum 1.5 grams fiber per 100 kcal. Check here which products/meals are suitable for persons with overweight.
 

Objectives:
Does vegetable and/or fruit consumption reduce metabolic syndrome (MetS)?

Study design:
This review article included 20 cross-sectional studies, 1 case-control study and 5 cohort studies.

Results and conclusions:
The investigators found in 16 studies when comparing the highest versus the lowest category of vegetable consumption a significantly reduced risk of 11% [overall multivariable-adjusted RR = 0.89, 95% CI = 0.85-0.93, p 0.001] for metabolic syndrome.

The investigators found in 16 studies when comparing the highest versus the lowest category of fruit consumption a significantly reduced risk of 19% [overall multivariable-adjusted RR = 0.81, 95% CI = 0.75-0.88, p 0.001] for metabolic syndrome.

The investigators found in 8 studies when comparing the highest versus the lowest category of vegetable and fruit consumption a significantly reduced risk of 25% [overall multivariable-adjusted RR = 0.75, 95% CI = 0.63-0.90, p = 0.002] for metabolic syndrome.

The investigators concluded that vegetable and/or fruit consumption is negatively associated with metabolic syndrome. However, more well-designed prospective cohort studies are needed to elaborate the concerned issues further.

Original title:
Associations of vegetable and fruit consumption with metabolic syndrome. A meta-analysis of observational studies by Zhang Y and Zhang DZ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29506604

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